Fire-extinguisher



(No'ModeLL J. s; SHRAWDER.

FIRE EXTINGUISHER.

'INVENTOR WITNESSES:

N. PETERS, Phm-Lnno n mr. wasmn mn, D. c

NITED STATES JOHN S. SHRAWDER, OF UPPER DUBLIN, PENNSYLVANIA.

FIRE-EXTI-NGUISHER.

SPECIFICATION forming part of Letters Patent No. 311,204, dated January 27, 1885.

Application filed October 31, 1883. (No model.)

To all whom it may concern:

Be it known that I, JOHN S. SHRAWDER, of Upper Dublin, in the county of ontgomery and State of Pennsylvania, have invented certain new and useful Improvements in Fire Extinguishers.

The following is a specification of my improvements, reference being had to the accompanying drawings, wherein- Figure 1 is a central vertical section through the apparatus. Fig. 2 is a horizontal section through the same on a line with the center of the discharge-nozzle. Fig. 3 is a front elevation of the pump and pipes leading therefrom detached from the rest of the apparatus; and Fig. 4 is a top or plan View of the parts indicated in Fig. 8, showing also the position of the cylinders which contain the chemicals.

My invention belongs to that class of fireextinguishers which make use of carbonated water, or water charged with carbonic-acid gas, to extinguish fire.

It consists in a device whereby a continuous stream of water thrown from a pump, or supplied by other means, may be charged in its passage through the apparatus with the chemicals whose combination will evolve carbonic acid, the solution of the chemicals and their subsequent union being effected just previous to the discharge of the stream. I thus not only free the apparatus from all pressure except that produced by the pump or other means of supply, but by charging the water. with the chemicals after it has passed the pump I avoid the corrosion of the valves, &c., which takes place when the solutions themselves are pumped; and I also completely isolate the chemicals from the water-reservoir when the machine is not in use, and thus proteot them from dampness and the vessels containing them from corrosion.

To these ends my invention comprises, primarily, the combination of the following. elements: A pump or other device for producing a supply of water, provided with two dis charge-pipes, respectively connected with two isolated cylinders or vessels for containing in a dry state the chemicals, whose .union in solution shall produce the carbonic-acid gas,. and separate discharge -pipes, which, after leading from said cylinders,unite in acommon chamber adjacent to the nozzle or final dis- Q, at the bottom of the tank, a handle,

charging-pipe of the apparatus, and means for regulating the supply of water to the respective cylinders. It further comprises the combination, with this principal group of elements, of a means of direct communication between the water-supply pipe and the discharge-nozzle,whereby the stream may be diverted from passing through the chemical-receptacles, thus permitting the use of water alone when desired, and econoinizing the chemicals for a more urgent moment.

Other novel features of construction and minor details, which will be hereinafter mentioned, are also included in my invention.

The form of apparatus shown in the drawings I deem preferable, as it embodies, in addition to the elements referred to above, and in immediate connection therewith, a water tank or reservoir and a pump; but, obviously,

this tank may be dispensed with and the water obtained from any convenient source of supply. Furthermore, the pump shown in the drawings need not be attached immediately to the apparatus, it being only essential that the discharge-pipe of the pump (or of the device whereby the flow of water is produced) be suitably connected with the respective cylinders, so that the two chemical solutions are formed'separately, and not until after the water has passed from the pump, 8rd, and are not brought together for the evolution of gas until after they have emerged from the cylinders and are about to be ejected from the apparatus.

In the drawings, A is a water-tank, of sheet metal, preferably of cylindrical form, and containing within it the other portions of the apparatus. Said tank is provided with a removable cover, R, and should also have abail or other suitable means for carrying it.-

B isapump-cylinder, having an inlet-pipe, P, and valves S, of the ordinary construction.

The discharge-piped. of the pump leads to a chamber, a, iuwhich is a three-way cock, 0.

When in the position shown in Fig, 2, the passage in this cock 0 leads to a cross-pipe, J, branching in each direction and communicating with the pipes D and D, which pipes D D differ in caliber fora reason and in a proportion to be hereinafter explained. The

pipes D D descend to the bottom of the-apparatus and enter the lower ends of the cylinders E E, respectively, where they terminate in perforated discharge-nozzles cl d. The cylinders E E are preferably constructed of copper, or some metal not easily oxidized, and their respective capacities differ in the same proportion as the pipes D D. Openings are provided at the top of the cylinders for charging them with chemicals, and these openings are tightly closed by means of screw-caps K K, respectively, having washers of rubber or other suitable material. Near the top of the cylinders E E are discharge-pipes G G, re 'spectively, whose orifices are protected by wiregauze screens 6 6. These discharge-pipes are provided with check-valves r r, of the usual construction, to prevent backflow into the cylinders, and thence lead to a pipe, H, which forms what may be termed a combiningchamber, the continuation I of this pipe H being the discharge-nozzle of the apparatus, to which a hose may be coupled, if desired. This discharge-nozzle I is also provided with asecondary supply-pipe, N, which leads thereto from the chamber a, the communication being thus direct between the pump and the discharge-nozzle I when the three-way cock 0 is turned at right angles to the position shown in Fig. 2, and the passage of the water through the cylinders being thus prevented.

As a convenient means of indicating the position of three-way cock, I provide a dialplate, M, having the words Gas and \Vater inscribed at the respective points over which the handle 0 of the cock 0 stands when the water is passing through the cylinders, or direct to the nozzle I.

The difference in size of the cylinders E E and their connections is determined by the respective and proper proportions of the chemicals used to evolve the carbonic-acid gas, the combined capacities of the two inlet-pipes D D being not substantially greater than the capacity of the pump-discharge pipe T.

I prefer to employ bicarbonate of soda and.

oxalic acid, both in crystals, in which case the quantity of acid proper to decompose a given quantity of bicarbonate is in the ratio of about four to one of the latter, and the cubic capacity of the parts referred to is therefore in that proportion. In cases, however, where it is desired to use other chemicals, the relative proportions should be varied to correspond with the necessary bulk and solubility of each.

To prepare the apparatus for use, the larger cylinder E is charged with the carbonate of soda and the smaller cylinder E with the 0X- alic acid. The caps K K are then screwed tightly on and the tank A is filled with water.

To insure the dryness of the contents of the cylinders, the handles of the three-way cock 0 should be turned over the mark Water on the dial M, as this cuts off all communication between the pump-chamber and the cylinders.

When it is desired to use the apparatus, the threeway cock 0 is turned into the position shown in Figs. 2 and 4 (the handle 0 being then over the word Gas on the dial M) and thepumpisactuated. Thewaterthuspumped is forced in separate streams into the cylinders E E, and in their passage through the chemicals contained in each these streams take up, respectively, the proper amounts thereof, the loose mass of crystals affording but little resistance to the flow. On rising to the top of the cylinders the solutionsof salt and acid pass out, respectively, through the pipes 'G and G, the screens e e preventing the passage of any foreign matters which might clog the pipes. The two solutions then meet in the chamber H,where they combine and produce the carbonic-acid gas, with which the water prior to its exit from the nozzle I is charged. Should it be desired to throw a stream of water alone, the cock 0 is turned until the handle is over the mark Water on the dial, whereupon the stream passes direct from the pump to the nozzle I; but at any moment the stream may be instantly changed to a carbonated one. This capacity of the apparatus is highly useful, as it permits the operator to economize the chemicals when it is found that a water stream is sufficient, still keeping the gas-generator in readiness for immediate use, should the emergency arise.

I am aware that it is not new to construct fire-extinguishers with duplicate reservoirs for chemicals, each of which is intermediate be tween the water-supply and the nozzle, such an arrangement being shown in Letters Patent No. 97,894, dated December 14, 1869. The reservoirs in said patent were not, however, intend ed for simultaneous passage of the water stream, the object being merely to provide a second reservoir to use after the first should be exhausted; nor is the said device capable of use in the manner above set forth, as essential to my invention, since the inlet-pipe of each of said duplicate reservoirs was necessarily equal in size to the main supply-pipe, and consequently the water stream could not be divided so as to pass simultaneously through both, but would take the first course through one alone.

In my invention the relative sizes of theiulet-pipes and main supply-pipe are such that the water stream must be divided so as to pass simultaneously through both cylinders.

Having thus described my invention, I claim i 1. The combination, in a chemical fire-extinguisher, of the following elements: apump for supplying water, a discharge-pipe leading therefrom to two separate inlet-pipes whose combined capacity is not substantially greater than the capacity of said discharge-pipe, two chemicalreservoirs into which said inletpipes, respectively, lead, and two separate exitpipes leading from said reservoirs and uniting in a common discharge-nozzle, said elements being arranged (with reference to the travel leading from said cylinders, a combiningof the water stream) in the order mentioned, chamber into which said exit-pipes lead, and a and for the purposes set forth. final exit-pipe adjacent to said combining- 2. The combination, in a chemical fire-exchamber, said tank forming an inclosure for 5 tinguisher, of the following elements: a tank, the other elements of such combination, sub 1 a pair of chemical-reservoirs within said tank, stantially in the manner specified.

but isolated therefrom and from each other, a JOHN S. SHRAVVDER. pump having an inlet communicating with Witnesses: said tank, and separate supply-pipes which WM. H. MYERS,

o lead into said reservoirs, separate exit-pipes J. WALTER DOUGLASS. 

